Concered with "Grade": F+

[faulty_damper]

This is the first time I've heard so much talk about "grade" from other piano students while reading these forums.  What is so important about the "grade" of a piano piece?  Are you concerned because you just got past your music theory exam Grade 5 and are now working toward 6 and think you are unable to play something that is graded higher than your grade?  I don't get it.  I've never taken those exams before and don't intend to do so even though my teacher does teach that way to the other students.  Those grade levels are, to use a concocted word, balognious!  And after Grade 8, after passing it, is there something else motivating you keep playing or has all those years of practice come to an end like many other students?

I don't get.  (But really, I do get it.  I saw it with my sister after she passed her Grade 8 exam - didn't bother to touch anything white or black for a long time.  But now she is playing again but only because of an opportunity to make money... compelled now not by those Exams but by another goal.)

Just wondering about what grade a piece would be classified signifies something about you, whatever it is.  But here's my list of Grades of pieces I play ( 1-8 ):

Joplin: The Entertainer, easy arrangement.  Grade 8. (When I first started playing piano)
Joplin: The Entertainer.  Grade 5.  (I didn't even know that the easy arrangement was an easy arrangement and was surprised there was the original version.)

Beethoven: Op.27-2 1st Mvm't.  Grade 4. (When I first started playing this piece)
Beethoven: Op.27-2 1st Mvm't.  Grade 6. (What I consider now to be more difficult to play.)

... These two examples are without reference to any Piano Exam Book pieces but are really just a scale of 1-8.

To a beginner, anything would seem to be difficult.
To a novice, it becomes less so.
To an advanced, those pieces would seem easy, no?

So what is the concern with "Grade"?